Device for measuring the lifting stroke of a track jack



Nov. 21, 1961 F. PLAssl-:R ETAL DEVICE FOR MEASURING THE LIFTING STROKE OF' A TRACK JACK Filed June 22, 1959 2 Sheets-Sheet l mww l Nov. 21, 1961 F. PLAssER ETAL DEVICE FOR MEASURING THE LIF'TING STROKE OF A TRACK JACK Filed June 22, 1959 2 Sheets-Sheet 2 United States 3,009,251 DEVICE FR MEASURING THE LIFTING STROKE F A TRACK JACK Franz Plasser and Josef Theurer, both of .lollannesgasse 3, Vienna, Austria Filed June 22, 1959, Ser. No. 821,934 Claims priority, application Austria, .lune 20, 1958 4 Claims. (Cl. 33-169) The present invention relates to track lifting machines and more particularly to a measuring device for readily determining the extent of the liftingl stroke effected by a jacking means arranged to raise a track portion to a predetermined level.

In conventional railroad track maintenance and repair practice, the desired track level is determined by a surveying team or apparatus advancing along the track ahead of a track lifting car. if the track level is found to require correction, the surveyors mark the required extent of raising the track at any given location. A track lifting car with a track jack is then moved to this location and the jack is operated to lift the track portion at this location to the desired level.

Heretofore, the desired extent of lifting the track was noted by the surveyors at or on the tie to Ibe lifted, for instance Dy suitable chalk marks, and the track then had to be viewed optically during lifting from appropriate fixed points -to control the raising operation and to limit the lifting stroke to the desired extent. This operation has required a number of operators and considerable time.

lt is the principal object of the present invention to simplify the control of the lifting stroke of a track lifting mechanism and to mount a lifting stroke measuring device directly on the track lifting car for automatic determination of the extent of the lifting stroke during the lifting operation.

The measuring device of this invention comprises essentially a footpiece arranged to contact and rest upon the surface of the roadbed ballast and a vertical measuring means which is vertically freely movable in relation to the fixed footpiece and which has an element engageable by the track and movable thereby when the track is lifted, whereby the lifting stroke determined by the increased spacing between the fixed footpiece and the rising track may be readily read off the measuring means which rises with the track. Since the lfootpiece rests on the ballast during the lifting operation and does not change its position, it serves as a reliable fixed reference point for the determination of the lifting stroke. The track jacking means itself may be any such means found suitable for the purpose, for instance a known hydraulic track jack.

ln accordance with one preferred embodiment of this invention, the footpiece of the measuring means is mounted on the track lifting car independently of the track lifting means and, in its operative position, rests on the roadbed ballast by the force of gravity. Such a gravity-controlled footpiece merely contacts the surface of the ballast and does not sink into it, thus providing a very accurate fixed control point which does not move during the lifting operation and thus enables a highly accurate determination of the lifting stroke to be made.

According to another embodiment of the invention, the measuring means is mounted on the track jacking means itself and the footpiece of the track jack serves as the footpiece and reference point for the measurement of the lifting stroke. While the footpiece of the jack will sink slightly into the bed during the lifting operation and thus somewhat impair the accuracy of the lifting stroke measurement, this embodiment has the advantage of involving fewer parts and simplifies the control and operation of the track lifter.

3,009,251 Patented Nov. 21, 1961 ECC Any measuring device adapted to measure the vertical distance from a fixed point may be used for the purposes of the invention and a great variety of specific structures may be adopted. Since the track lifting car rises with the Itrack during the lifting operation, it is sufiicient to bring any portion of the car chassis in measurable relationship to any part connected with the fixed footpiece.

A preferred measuring means according to this invention includes a sleeve or like measuring member freely slidable on a vertical rod and provided with a probing means, for instance a horizontally extending arrn, mounted for contact with the upper surface of the rail. This structure makes it possible to associate with the vertically movable measuring member an indicator element which is also vertically movable in relation to the fixed footpiece as well as the measuring member but which may be held in fixed position during the lifting operation. In this manner, the initial position of the vertically moving measuring member may be fixed by the indicator at the beginning of the lifting stroke so that the extent of the lifting stroke may be readily read from a scale on the measuring member by the alignment of the temporarily fixed indicator with a calibration of the scale.

In such a measuring means, the indicator element is preferably held in a zero position at the beginning of the lifting stroke. For this purpose, the invention provides a resilient means, such as a suitably biased spring means, for suspending or supporting the indicator element in a predetermined vertical position. Thus, a reading of the scale will immediately show the extent of the lifting stroke, the zero calibration mark on the measuring scale corresponding to the level at which lifting -was begun.

The above and other objects, advantages and features of the present invention will become more apparent in the following detailed description of certain preferred ernbodiments thereof, taken in conjunction -with the accompanying drawing wherein FIG. l is a front View, partly in section, of one ernbodiment of a rail lifting system with its actuating circuits, according to the invention;

FIG. 2 is a sectional view along line 2-2 of FIG. l and showing certain details of the jacking means as well as the lifting stroke measuring means;

FIG. 3 is an enlarged section along line 3-3 of FIG. 2; and

FIG. 4 is a front view similar to FIG. 1 of another embodiment of the invention.

Referring now to the drawing and more particularly to FIGS. 1-3, the -rail lifting mechanism is shown to include a jacking means actuated by a lift cylinder 1 which has connected thereto conduits 18 and 19 for selectively supplying a pressure fluid, such as a hydraulic liquid, to one or the other of the cylinder chambers defined by piston 2 slidably mounted in the cylinder. A compression spring It is mounted in the upper cylinder chamber to bias the piston downwardly. Piston rod 2 has its inner end attached to or integral with piston 2 while its outer end carries a footpiece constituted by plate 3. The footpiece is linked to the outer piston rod end by pivot means 3' to assure a secure and indisplaceable engagement of the footpiece on ballast bed lll. If desired, the firmness of the footing on the bed may be increased by providing the plate 3 with downwardly directed projections, teeth or the like which sink into the ballast when the plate engages its surface. The bias of spring 1' is sufiicient to press footpiece 3 against the surface of the roadbed but is not large enough to initiate jacking.

Hydraulic or similar pressure-actuated rail lifting yor jacking means of the illustrated type are 'known and, as schematically shown, the lift cylinder 1 is fixedly mounted on a bracket 4 extending from chassis 5 of a car movable alongrails 8 on wheels 7 which are journaled on axle 6.

As conventional, the rails 8 rest on ties 9 to form the usual railroad track. Also mounted on the car chassis is a rail gripping means 31 of any suitable structure and schematically shown for purposes of illustration to be constituted by a rail gripper as described and claimed in our U.S. Patent No. 2,847,943, granted August 19, 1958. Other means for gripping the rail while being jacked up may be used, of course, the present invention not being concerned with this aspect of the mechanism.

In the illustrated embodiments, the jacking means is hydraulically operated. For this purpose, the hydraulic pressure fluid lines 18 and 19 are connected to a threeway slide valve 20 whose control handle 20 operates the valve to produce selected positions I, II and III (positions I and III being shown in broken lines). Storage tank 21 holds a supply of hydraulic liquid, such as oil, and pump 23 delivers the liquid from the supply to valve 20 over conduit 22. A return conduit or line 24 branches off line 22 and carries relief valve 25 to protect the hydraulic circuit against excess pressure. A conduit 26 returns fluid from valve 20 to storage tank 21 during idling of the jacking means.

The measuring device according to the invention for determining the extent of the lifting stroke of the abovedescribed jacking means will now be described. As shown in the embodiment of FIG. 1, the measuring device includes a measuring sleeve 11 which is slidably mounted on piston rod 2 for free vertical movement thereon. The measuring sleeve carries a calibrated measuring scale 11 and has a laterally extending fixed arm 12 substantially perpendicular to the jacking means and arranged to contact the upper surface of rail 8, thus constituting a rail probing means.

As more clearly illustrated in FIGS. 2 and 3, the measuring sleeve is provided with a longitudinally extending slot 13 wherein there is guided a pin or bolt 13 projecting outwardly through the slot 13 and carrying an indicator element 14. Alignment of element 14 with a given calibration of scale 11 produces the desired reading, as will be more fully explained hereinafter.

Pin 13 with its fixedly attached indicator 14 is guided not only in longitudinal slot 13 of measuring sleeve 11 but in a corresponding longitudinal slot 14 of piston rod 2 so that the vertical position of the indicator may be adjusted. The pin with its indicator is mounted in a slidable ring 15 to provide improved guide means therefor, the entire slidable indicator assembly 13', 14, 15 being biased by spring means 16. The spring means bias is sucient to produce a tendency of upward movement in the indicator assembly but is not strong enough to overcome the weight of measuring sleeve 11. Rather, the spring means 16 has just enough force to hold the indicator 14 always at the upper end of slot 13, regardless as to the vertical position of measuring sleeve 11. The respective ends of spring means 16 are attached at 16' to an extension of lift cylinder 1 and at 16 to the slidable ring 15.

Ring 15 carries a piece 15' of magnetic material, which is associated with a longitudinally extending electromagnet 17 laterally spaced from the measuring sleeve and mounted on piston rod 2 by means of arms 17 and 17". As shown, the vertical position of the electromagnetic means may be adjusted since the arms 17 and 17" are keyed to the piston rods by means of set screws.

An electric current supply source constituted in the illustrated embodiment by storage battery 21 is connected to electromagnetic means 17 by means of electric conductors 28 and 29 leading to the respective terminals of the storage battery. The electric circuit may be opened and closed by a switch 30 actuatable in position III of hydraulic valve control handle When electromagnet 17 is energized, it holds the magnetic piece 15 of the indicator assembly in position while the measuring sleeve 11 continues to be freely slidable in ring 15. The relative movement between the magnetically fixed indicator assembly and the measuring sleeve moving upwardly with rail 8 as the latter is jacked up, provides the measurement of the lifting stroke, as will now be more fully explained in the description of the operation of this system.

Assuming valve 20 to be in position I, pressure fluid will be delivered through lines 22 and 18 into the lower chamber of lift cylinder 1 whereby piston 2 will be forced upwardly against the bias of spring 1'. In this position, therefore, the jacking means is inoperative, the footpiece 3 is lifted above the roadbed and the ties 9, and thc car upon which the entire lifting mechanism is mounted may be freely moved on the track to the location where track lifting or leveling is to be effected. The arm 17" of electromagnet 17 takes along the measuring sleeve 11 as the piston rod 2 moves upwardly, thus lifting fixed arm 12 off the surface of rail S.

When the desired location is reached, the car is brought to a stop in such a position that the jacking means operates between two ties 9. Handle 20 is now thrown into position II in which all pressure fluid supply to the lift cylinder is cut off and the fluid is returned to the storage tank 21 through line 2'4 and relief valve 25. The fairly powerful compression spring 1 is now free to push the footpiece 3 against the surface of ballast 10, causing the fixed arm 12 of measuring sleeve 11 to contact the upper surface of rail 8. Arm 12 rests on rail 8 under the weight of sleeve 11. In view of the predetermined bias of spring means 16, indicator 14 is held at the upper end of slot 13 of the measuring sleeve and thus is aligned with the zero calibration of scale 11.

This is the position of the system illustrated in FIG. l which also shows the rail gripping means 31 engaging rail 8 so that the lifting operation proper may now be begun.

For this purpose, valve 2) is thrown into position III. In this position, the valve control handle 20' closes the switch 30 to energize electromagnet 17 and thus hold the indicator assembly in the position determined by the original position of rail 8 as indicated by probing arm 12. Simultaneously, pressure fluid is delivered through line 19 to the upper chamber or lift cylinder 1 so that feotpiece 3 is hydraulically pressed downwardly against the roadbed and causes the track to be lifted, rail 8 being gripped by rail clamping means 313. The extent of the lifting stroke may now be readily read from scale 11 since the measuring sleeve 11 glides freely upwardly on the piston rod 2 and in magnetically fixed ring 15 under the pressure of the upwardly moving rail 8 pushing probing arm 12. When magnetically fixed indicator 14 shows the desired extent of the lifting stroke on scale 11', the lifting operation is terminated.

If desired, a suitable stop means (not shown) may hold the jacking means in position long enough to make it possible to x the lifted track in its new position, for instance by tamping ballast under the ties in a manner well known per se. After this, the car may be moved on to a new location and the operating cycle is there repeated.

The embodiment of FIG. 4 is in many respects similar to that of FIGS. l to 3, the hydraulic and electric circuits being identical with that of FIG. l and, therefore, being omitted from this figure. The essential difference between the two embodiments resides in the fact that the measuring device in the embodiment of FIG. 4 is mounted entirely independently of the jacking means While it is arranged on the jacking means in the other embodiment. As in the embodiment of FIG. 1, the entire system is arranged on chassis 5 of a car movable on wheels 7 mounted 'on axle `6 over rails 8, the rails resting on ties 9. The hydraulic jacking means is substantially identical with that of FIG. l and includes a lift cylinder 1a supported on beam or bracket 4a which, in turn, is mounted on a cross beam 5a of chassis 5. Pressure fluid is delivered selectively to the chambers of cylinder 1 through pipes 18 and 19 so that piston rod 2a may be vertically reciprocated in the cylinder. Footpiece 3a is linked to the outer end of the piston rod at joint 3a', all

of these elements and operations being the same as in the embodiment of FIG. 1. This also applies to the rail gripping means 31 which is mounted on the chassis.

While the individual elements and general operation of the measuring device of FIG. 4 also are similar to those of FIG. l, the entire device is independently supported. Thus, a guide rod 27 is slidably supported in brackets 23 mounted on chassis 5 and slidably supports measuring sleeve 11a, the independently supported guide rod 27 serving the function of piston rod 2 as support for the measuring device. The entire device tends to descend under its own weight until the footpiece 27 engages the surface of ballast it), footpiece 27 being linked t'o the outer end of guide rod 27 similarly to the mounting of footpiece 3a on piston rod 2a. The entire measuring device may be moved upwardly and away from the roadbed and track by means of a rope or wire 30 attached to the upper end of guide rod 27 and guided by pulley 29 mounted on chassis S. Any other suitable means for pulling the measuring device upwardly may, of course, be provided as long as it is designed to remove the footpiece 27 far enough from the track to permit the car to move on.

All other elements of the measuring device being identical with that of FIG. l, the same reference numerals with an added a have been used therefor in FIG. 4 to designate like elements, thus making a repetitive description thereof unnecessary.

The operation of this embodiment is identical with that of the first-described system, except for the following details:

Before the lifting operation proper is begun, rope 30 is released to permit -the measuring device to descend under its own Weight whereby the footpiece 27 will come to rest on ballast 10. This also causes the measuring sleeve 11a to contact the upper surface of rail 8 with its probing arm 12a, the sleeve being frech, slidable on the guide rod 27 and always tending to move down by force of gravity. The gripping means 31 is now actuated and the jacking means is operated to raise the track. As the rail 8 is raised, it takes along probing ann 12a and its carrier sleeve 11a while footpiece 27 remains resting on the roadbed lby force of gravity. The extent of the lifting stroke may, then be read on the scale 11a by means of indicator 14a which is magnetically held xed by electromagnet 17a in the same manner as hereinabove described.

While the invention has been described speoically in connection with two now preferred embodiments, it will be understood that many modiications and variations in structural details may readily occur to the skilled in the art, particularly after benetting from the present teaching, without departing from the spirit and scope of this invention as defined in the appended claims.

What we claim is:

1. A device for measuring the vertical stroke of a jacking means for lifting a track off a roadbed, comprising a footpiece arranged to contact and rest upon the surface of the roadbed, a rod supporting the footpiece, a measuring sleeve which is vertically freely movably mounted on the rod, a vertically calibrated scale on the sleeve including a zero calibration, an indicator means vertically movable on and in relation to the measuring sleeve and to the footpiece, a resilient means biased to hold the indicator means aligned with said Zero calibration, means actuatable to hold the indicator means in the zero position, control means lfor actuating the said holding means at the beginning of the lifting stroke, and a laterally extending probing element mounted on the sleeve and engageasble -by the track for movement therewith when the track is lifted.

2. The measuring `device of claim 1, further comprising a ring slidabl-y mounted on the measuring sleeve for supporting the indicator means and a pin means diametrically, extending through said ring and guided in vertically extending slots in the rod and the measuring sleeve lfor guiding the ning during its Vertical movement.

3. 'Ihe `measuring device of claim l, wherein said indicator means includes a magnetic element and said holding means is a vertically extending electromagnet adjacent said rod, the control means therefor being an eiectric circuit energizable at the beginning of -t-he lifting stroke.

4. A device for measuring the vertical stroke of a jacking means for lifting a track off a road-bed, comprising a footpiece arranged to contact and rest upon the surface of the roadbed, a rod supporting the footpiece, a measuring means which is vertically `freely movably mounted on the rod, a vertically extending calibrated scale on the measuring means, `an indicator means vertically movable on and in relation to the measuring means and to the footpiece, means actuatable to hold the indicator means in position, and control means for actuating the said holding means at lthe beginning of the lifting stroke.

References Cited in the file of this patent UNITED STATES PATENTS France Apr. 3, 1939 

